v15 - UX: Child nodes sort order in sidebar

[tbolon]

Nodes in the sidebar seems to always be ordered by Key.

The collection view can be customized to use a different sort order, but this rule will not be used for the sidebar.

It's problematic for news for example, where content is created in a chronological order: the most recent articles will always be last and so only the oldest articles will be visible when expanding the sidebar node.

If you have a lot of nodes (like any blog or newspaper) the sidebar nodes will be mostly useless because of this.